On my site I use $ENV{'REDIRECT_REMOTE_USER'} to get the username of the user and it is working just fine for any "regular" pages or pages that receive information from the GET form action. However, when I set the form action to POST on the resulting page $ENV{'REDIRECT_REMOTE_USER'} is empty and I cannot do anything with the information because I no longer know the user. This has only been a recent problem.